hi their im having problems with my truck.its a 89 f150 5.8 with the c6 auto sat for about 3 years.100,000 miles it has a very bad miss to it and hesitates bad on accel. iv done the following
drained gas tanks and cleaned them. tested fuel press 32psi steddy at idle koeo i have to turn key on and off multiple times to get fuel press on gauge is that right? regulater is fine pops up 5 psi when vac line is disconected. changed oil.
new motocraft copper plugs gapped to spec,pcv valve, new wires routed right so no crossfireing.cap and rotor,egr valve (old one would not hold vac.) checked for vacuum leaks cant seem to find any,tested every sensor i can think of with manual all seem to be in spec.did a comp check wet and dry and every things in spec.i did find a orange wire disconected behind the uper intake manifold dont know where that is supost to be conected.the only code im getting is 44 but the smog pump is no longer there.all the lines for that are caped off could this be the cause? the valves behind the engine are all ok not leaking. any help would be great as im about to pull all my hair out!

 

Howdy and welcome to the basement.

I'll try again tomorrow, but with the few I've had so far tonight, I can't get through your post without periods.

Adrianspeeder

 

Hi thanks for the reply. Sorry about the long page with no periods. The truck idles very poorly. It had sat for close to three years. I started by doing a full tune up plugs wires cap rotor, it did run a lot better after that. But still runs like crap until its at about 1000 rpm. I also replaced the egr valve do to it not holding vacuum. I replaced the fuel filter. I'm starting to wonder about fuel injectors. Any ideas?

 

If it sat that long then the fuel system is most likely gummed up. Change the fuel filter and run a good fuel system cleaner through it.

 

Is this 3+ year old gas in the tanks?

Adrianspeeder

 

Ok this is what iv done so far. it has 100,000 miles on it .it has a very bad miss to it and hesitates bad on accel. iv done the following
drained gas tanks and cleaned them. tested fuel press 32psi steddy at idle koeo i have to turn key on and off multiple times to get fuel press on gauge is that right? regulater is fine pops up 5 psi when vac line is disconected. changed oil.
new motocraft copper plugs gapped to spec,pcv valve, new wires routed right so no crossfireing.cap and rotor,egr valve (old one would not hold vac.) checked for vacuum leaks cant seem to find any,tested every sensor i can think of with manual all seem to be in spec but the tps had a little jump in voltage when testing but i dont think thats the problem.did a comp check wet and dry and every things in spec.i did find a orange wire disconected behind the uper intake manifold dont know where that is supost to be conected.the only code im getting is 44 but the smog pump is no longer there.all the lines for that are caped off could this be the cause? the valves behind the engine are all ok not leaking. any help would be great

 

I'm going to try a new tps tomorrow. I'm hoping that's the problem, as it spikes in voltage a lil bit.I checked the timeing today.its set at 10 deg. btdc with spout removed. the distributer is fine also.Could a cracked exaust manifold cause a misfire even if my o2 sensor is not sensing it? I'm getting to my boiling point with this thing! I want to get this thing running well so it can be my daily driver.

 

Update tps made a differance but did not fix the problem. What should the fuel pressure be on this thing?

 

should not have to prime multiple times to get enough fuel pressure to run smoothly, well on a truck that has only been sitting a few days. Low pressure pump might be weak, and HP pump pulling all the fuel. Try unplugging the low pressure pump and seeing what the results are.

 

Having problem with truck running to rich code 42 (r) I have replaced egr and valve, spark plugs wires cap and pin good. New o2 sensor. New coolant temperature sensor new vac lines and no leak new tp sensor. Today replaced the coolant sensor and was going to check the codes. Turned truck off put reader on there then started truck turned reader on truck died and will not start need help any ideals thanks

 

Hey fords, did you disconnect the battery before you replaced the tps? You have to do that anytime you replace any sensor related component, so the computer can learn what the new values are. After you replace any said components, you can expect about 10 miles worth of crappy driving until the computer relearns how to drive. Also, like jgger and Adrian said, if you have 3+ years of gas sitting idle in the system, there's going to be a lot of varnish issues. Peace, Dave.

 

Ok I finally maybe on to something while I was driving the truck. I herd a small whine coming from the high press. Pump on the frame. So I went to the parts store and got a new one. While I was at it I turned the key on with pump disconnected to test the in tank pump and salector valve sprayed a nice powerful stream of clear fuel.so I figgerd the high pressure pump was bad. So it got replaced boom powers back! Seemed to idle good to then about a half hour later the pump started whining agin now I'm stumped. Both gas tanks are clean.The intank pumps are working i can hear them both when salected .Could my salector valve be party stuck? Also I read somewhere online that you could use a in tank pump out of a 91-96 ford truck to bypass all the bs is that posible? Because I have a gas tank and pump from a 91 f150 that was brand new when I had to sadly junk that truck due to a rusted frame. I would be very great full if that would work. Obviously I would have to figure out supply lines to the engine. Agin thanks for all the help keep the pointers coming

 

Oh and yes I disconnected the battery while replaceing the tps thanks.

 

Fords, do you have a box in the engine compartment with relays for the fuel pump? Reason I ask is because a buddy of mine was having problems with his vehicle. Somehow he ended up replacing the fuel pump. 3 times. Finally he saw a post somewhere that said to go out and smack that box around a bit. He did, and he hasn't had to replace his pump again and as far as I know, he hasn't had any issues since. (Too late to call him now). I do remember he was ticked off because he thought he got 3 bad pumps in a row. He didn't have an explanation as to why you'd smack the box, only thing I can figure is corrosion on the connectors. Something to look into, anyway. Good luck, keep us posted, Peace, Dave.

 

Fuel pump relay is brand new. that was the first thing I replaced. Also all of these problems this truck is having was the reason it was parked. I got it from a family member and he owned it since 1989. Any other thoughts? I'm getting so ticked off at this thing. I'm geting close to dumping the thing but its a very clean truck perfect int. and a very small amount of rust on the back wheel well. And as I'm sure most of you know here in MN. The winters are hard on cars so I'm probly not going to find one this nice so I want it fixed before it gets cold! Lol